You should read the Topic Start carefully.
OLED WIFI LoRa 32 is not the correct full name of your board.
Your board is one of the following:
- Heltec Wifi LoRa 32
- Heltec Wifi LoRa 32 V2
V2 will have “V2” marked on the PCB.
The available Heltec Wifi LoRa 32 boards are listed exactly as follows:
- Heltec Wifi LoRa 32
- Heltec Wifi LoRa 32(V2)
The board you select must match your hardware. Select V2 only if you have a real V2 board.
As described in the Topic Start ttn-abp.ino is the correct example sketch to start with.
Important is to use the correct pin mappings and corresponding software configuration settings for your board. These are also described in the topic start.
Also note the I2C (SCL, SDA) remarks for V2 in the Topic Start. These are essential for getting the OLED display or other I2C peripherals to work (after you have the basics working).
For the correct format of the LoRaWAN keys and ID’s see:
Format of Keys and ID’s for Arduino LMIC libraries [HowTo]